Question: Evaluate the following expression when $y = 3$ and $x = 8$. $4$ $y$ $ + 7$ $x$ $ - 9$
Solution: Substitute $3$ for ${y}$ and $8$ for ${x}$ $ = 4{(3)} + 7{(8)} - 9 $ $ = 12 + 56 - 9 $ $ = 59$